Various fasteners are known for securing an item to a hollow wall or partition by anchoring the fastener to the rear surface of the hollow wall via a hole provided therethrough. For example, one well-known toggle bolt employs a pair of hinged wings threaded onto a bolt and held in a normally open or outwardly extending position by means of a spring. The wings are folded toward one another for insertion through a previously drilled hole in a hollow wall, such as a plaster or plasterboard wall, the wings snapping open after passage through the hole. The open wings are drawn via the threaded bolt against the rear wall surface and the bolt tightened against the front wall surface to anchor the fastener, to the front end of which is connected a picture hook, bracket or other item being fastened to the wall. Such toggle bolts of conventional construction are widely employed and provide good holding action for many purposes. However, a hole must be provided in the wall substantially larger than the bolt diameter to accommodate the relatively large hinged wing assembly which must be passed through the hole to the rear of the wall for anchoring therein. Moreover, the mounting hole must be drilled or reamed by a separate drill bit or other suitable tool. As a further disadvantage, the wing assembly can wrongly be installed backwards on the bolt in which event firm anchoring is not achieved. The wings must also be drawn against the rear wall surface to tighten the bolt and prevent rotation of the wings.
Various alternative toggle bolt structures have been proposed heretofore. In U.S. Pat. No. 3,782,238 an anchor plate to which a bolt is threaded and secured to the rear surface of a hollow wall is configured to serve as a drill bit for provision of a mounting opening in the wall. When use as a drill bit, the plate must be disassembled from the fastener bolt and employed with a conventional hand or power drill, and after the hole is made, the plate must then be reinstalled onto the fastener bolt at a specially configured end thereof such that the plate is colinear with the bolt axis for insertion through the mounting hole. After insertion of the bolt and plate through the hole, the bolt is twisted to cause the mounting plate to assume a transverse disposition for anchoring against the rear wall surface as the bolt is tightened. Other fasteners of known construction are shown in U.S. Pat. Nos. 2,908,16; 1,409,626; 608,717; and 2,578,515.